Long-term clearance of hepatitis C virus following interferon α-2b or peginterferon α-2b, alone or in combination with ribavirin.

Sustained virologic response (SVR) is the standard measure for evaluating response to therapy in patients with chronic hepatitis C (CHC). The aim of this study was to prospectively assess the durability of SVR in the pivotal studies of peginterferon (PEG-IFN) α-2b or IFN α-2b. We conducted two phase 3b long-term follow-up studies of patients previously treated for CHC in eight prospective randomized studies of IFN α-2b and/or PEG-IFN α-2b. Patients who achieved SVR [undetectable hepatitis C virus (HCV) RNA 24 weeks after completion of treatment] were eligible for inclusion in these follow-up studies. In total, 636 patients with SVR following treatment with IFN α-2b and 366 with SVR following treatment with PEG-IFN α-2b were enrolled. Definite relapse (quantifiable serum HCV RNA with no subsequent undetectable HCV RNA) was reported in six patients treated with IFN α-2b and three patients treated with PEG-IFN α-2b. Based on these relapses, the point estimate for the likelihood of maintaining response after 5 years was 99.2% [95% confidence interval (CI), 98.1-99.7%] for IFN α-2b and 99.4% (95% CI, 97.7-99.9%) for PEG-IFN α-2b. Successful treatment of hepatitis C with PEG-IFN α-2b or IFN α-2b leads to clinical cure of hepatitis C in the vast majority of cases.

Optimized threshold for serum HCV RNA to predict treatment outcomes in hepatitis C patients receiving peginterferon alfa-2a/ribavirin.

It is unclear whether the current threshold for 'high' hepatitis C virus (HCV) RNA level (800,000 IU/mL) is optimal for predicting sustained virological response (SVR). We retrospectively analysed pretreatment HCV RNA levels and SVR rates in 1529 mono-infected and 176 HIV-HCV co-infected patients treated with peginterferon alfa-2a (40 kD) plus ribavirin. We improved the threshold for differentiating low and high viral load by fitting semiparametric generalized additive logistic regression models to the data and constructing receiver operating characteristics curves. Among HCV genotype 1 mono-infected patients, the difference in SVR rates between those with low and high baseline HCV RNA levels was 27% (70%vs 43%) when 400,000 IU/mL was used and 16% (59%vs 43%) when 800,000 IU/mL was used. In HIV-HCV genotype 1 co-infected patients, the difference was 51% (71%vs 20%) when 400,000 IU/mL was used and 43% (61%vs 18%) when 800,000 IU/mL was used. A lower threshold (200,000 IU/mL) was identified for genotype 1 mono-infected patients with 'normal' alanine aminotransferase (ALT) levels. No threshold could be identified in HCV genotype 2 or 3 patients. A threshold HCV RNA level of 400,000 IU/mL is optimal for differentiating high and low probability of SVR in genotype 1-infected individuals with elevated ALT.

Portal-systemic shunting in patients with fibrosis or cirrhosis due to chronic hepatitis C: the minimal model for measuring cholate clearances and shunt.

BACKGROUND: Measurement of portal inflow and portal-systemic shunt using cholate clearances could be useful in monitoring patients with liver disease. AIM: To examine relationships of cholate clearances and shunt to cirrhosis and varices and to define minimal sampling requirements. METHODS: Five hundred forty-eight studies were performed in 282 patients enrolled in the Hepatitis C Antiviral Long-term Treatment to prevent Cirrhosis (HALT-C) trial. Stable, non-radioactive isotopes of cholate were administered intravenously and orally, clearances (Cl(iv) and Cl(oral)) were calculated from [dose/area under curve (AUC)] and cholate shunt from [(AUC(oral):AUC(iv)) x (Dose(iv):Dose(oral)) x 100%]. RESULTS: Cholate Cl(oral) and cholate shunt correlated with prevalences of both cirrhosis and varices (P < 0.0001 for all). Peripheral venous sampling at 5, 20, 45, 60 and 90 min defined the minimal model. Linear regression of cholate shunt determined from five points within 90 min vs. the standard method of 14 points over 3 h yielded slope of 1.0 and intercept 0.5% (r(2) = 0.98, P < 0.0001). Results were identical in the 189 validation studies (slope 1.0, intercept 0.5%, r(2) = 0.99, P < 0.0001). CONCLUSIONS: Cholate Cl(oral) and cholate shunt may be useful in monitoring patients with liver disease. The 5-point model enhances application of cholate Cl(oral) and cholate shunt in the non-invasive assessment of the portal circulation.

Multimodality therapy and liver transplantation in patients with cirrhosis and hepatocellular carcinoma: 6 years, single-center experience.

The treatment of patients with cirrhosis and hepatocellular carcinoma (HCC) has improved dramatically over the past 10 years. We conducted a 6-year prospective study, using multimodality ablation therapy (MMT) combined with liver transplantation (LTx) for patients with cirrhosis and unresectable HCC. Subjects were classified as: group 1 (n = 35), intention to treat with MMT + LTx; group 2 (n = 16), contemporaneous LTx with "incidental" HCC on explants; group 3 (n = 94), MMT alone; and group 4 (n = 19), palliative care alone. MMT included trans-arterial chemo-embolization (54.4%), trans-arterial chemo-infusion (28.6%), and radio frequency ablation (17%). Group 1, with a mean wait time of 11.6 months pre-MELD era and 5.4 months post-MELD era, had a mean of 2.4 +/- 1.2 MMTs and achieved 1- 3-, and 5-year patient survivals of 100, 100, and 76%, respectively, which was not different from group 2 (incidental HCC), namely 93, 93, and 93%, respectively; or to a contemporaneous non-HCC LTx group: namely 84.3, 78.7, and 73.9%, respectively. Despite careful pretransplant HCC staging, 22.8% (8 of 35) group 1 subjects were understaged. Those subjects in group 1 with true T1-2 stage HCC achieved 100% cancer-free survival at 5 years. Only three cases of HCC recurrence occurred in our series, all of whom were understaged. Our data suggest that pretransplant MMT followed by timely LTx provides excellent disease-free survival at 5 years for patients with true T1-2 stage HCC and cirrhosis. Pretransplant HCC understaging contributes to posttransplant HCC recurrence after LTx.

Review article: management of patients with chronic hepatitis C virus infection and "normal" alanine aminotransferase activity.

BACKGROUND: Hepatitis C virus infection, a major cause of chronic liver disease, occurs with normal serum alanine aminotransferase activity in approximately 25% of patients. These patients have historically remained untreated but substantial evidence indicates liver damage, progression of disease and impaired quality of life in some individuals. AIM: To review the current management of patients with chronic hepatitis C and normal alanine aminotransferase activity. METHODS: This review represents the summary of discussions at a Clinical Workshop with a comprehensive literature searching of available databases (PubMed and Embase). RESULTS: Current limits defining normal serum alanine aminotransferase activity are not representative of a "healthy" status. Most patients with hepatitis C and normal alanine aminotransferase levels have histologically proven liver damage that, although generally mild, may be significant (> or =F2) in up to 20% of patients and progresses at approximately 50% of the rate in patients with elevated alanine aminotransferase levels. Some patients have persistently normal alanine aminotransferase activity and may have a more benign outcome, but a significant proportion (> or =20%) experience periods of increased serum alanine aminotransferase activity which may be associated with enhanced disease progression. CONCLUSIONS: A treatment approach that considers host and virus-related variables and optimizes patient and cost benefits may therefore provide more effective management of patients with chronic hepatitis C and normal alanine aminotransferase activity.

Breast-milk composition in women with cystic fibrosis: report of two cases and a review of the literature.

Breast milk was collected from two women with cystic fibrosis (CF) and data from the literature was reviewed. The sodium concentration was within normal limits, 11-24 mmol/L in colostrum and 7-8 mmol/L in mature milk. Normal physiologic changes in milk composition after parturition (decreases in Na and increases in lactose) and during individual feeding periods (increases in fat and decreases in protein) were observed. Concentrations of milk protein, fat, and sugars were normal when the pulmonary disease of these patients was mild. During exacerbations of pulmonary disease, the concentrations of milk macronutrients were reduced. Milk secreted by women with CF appears to be physiologically normal, safe for the infant, and breast-feeding by mothers with CF should no longer be discouraged. Variations in the macronutrient content of CF milk warrants routine monitoring of the mother with CF and the breast-fed infant, especially during exacerbations in the pulmonary aspects of this disease.

Biochemical and histologic evaluation of recurrent hepatitis C following orthotopic liver transplantation.

It is well recognized that hepatitis recurs in virtually all patients who undergo orthotopic liver transplantation for cirrhosis secondary to chronic hepatitis C (HCV). The present report describes the biochemical and histologic findings of recurrent hepatitis in 25 such patients. One patient was found to have hepatocellular carcinoma at the time of OLT and was excluded from further analysis. All post-OLT laboratory values were reviewed. Liver biopsies were performed on protocol 6, 12, 24, and 36 months following OLT. Additional biopsies were performed as necessary to evaluate abnormalities in serum liver chemistries. A total of 104 biopsies was obtained; hepatitis consistent with recurrent HCV was present in 68 (65%). Other biopsy findings included cytomegalovirus hepatitis; acute, chronic, or resolving rejection; cholestasis with or without an underlying hepatitis; steatosis, and centrilobular necrosis. Histologic hepatitis appeared in all patients within 12 months following OLT. Despite these histologic findings, serum ALT was normal for prolonged periods in over 50% of such patients. In all cases this hepatitis was mild and did not progress over a mean follow-up of 22 months (maximum 44 months), as judged by Knodell histologic activity score (mean score: 4.0 +/- 0.3). Five patients developed cholestatic jaundice, far out of proportion to the degree of histologic hepatitis. In 2 patients this was secondary to chronic rejection. The other 3 patients had drug-induced cholestasis that resolved after various medications were discontinued. HCV did not contribute to graft dysfunction in any of the 24 patients. To date, our data suggest that post-OLT hepatitis in patients with preexisting HCV is a relatively benign process. Severe cholestatic jaundice in such patients is not secondary to HCV, and should stimulate a search for other possible causes of graft dysfunction. The long-term consequences of recurrent HCV following hepatic transplantation remain to be determined.

Right lobe living donor liver transplantation.

BACKGROUND: The shortage of livers for transplantation has prompted transplant centers to seek alternatives to conventional cadaveric liver transplantation. Left lateral segmentectomy from living donors has proven to be a safe operation for the donor with excellent results in the pediatric population. Left lobectomy, conceived to supply more tissue, still provides insufficient liver mass for an average size adult patient. Right lobectomy could supply a graft of adequate size. METHODS: Donors were considered only after recipients were listed according to United Network for Organ Sharing (UNOS) criteria. Donor evaluation included liver biopsy, magnetic resonance imaging, and celiac and mesenteric angiography. The donor operation consisted of a right lobectomy uniformly performed throughout the series as described herein. RESULTS: Twenty-five right lobe living donor liver transplants were performed between adults, with no significant complications in donors. Recipient and graft survival was 88%, with three recipient deaths secondary to uncontrolled sepsis in patients at high risk for liver transplant; all three had functioning grafts. CONCLUSIONS: Right lobe living donor liver transplantation poses challenges that require a meticulous surgical technique to minimize morbidity in the recipient. Right lobectomies for living donation can be performed safely with minimal risk to both donor and recipient although providing adequate liver mass for an average size adult patient.

Hepatic lidocaine metabolism and complications of cirrhosis. Implications for assessing patient priority for hepatic transplantation.

The number of patients awaiting hepatic transplantation continues to exceed organ donation. As a result, many liver transplant candidates will develop life-threatening complications of their liver disease and not survive the pretransplant waiting period. Recent studies have demonstrated that hepatic lidocaine metabolism into monoethylglycinexylidide (MEG-X) can predict pretransplant survival. The present study was performed to determine if MEG-X could also predict pretransplant complications and thereby be useful in stratifying persons being evaluated for hepatic transplantation. A total of 57 patients with biopsy-proven cirrhosis underwent MEG-X testing. Of 57 patients, 30 (53%) developed life-threatening complications of their liver disease--i.e., variceal bleeding, grade II hepatic encephalopathy or worse, and spontaneous bacterial peritonitis. MEG-X values were greater in persons without complications of liver disease than in persons with complications (25.7 +/- 2.9 versus 14.7 +/- 1.4 ng/ml, respectively). No patients with MEG-X greater than 30 ng/ml developed a major complication. No significant difference in any of the standard liver function tests existed between persons who developed complications and patients who did not. In this group of 57 patients, 4 (7%) died from complications of cirrhosis. Mean MEG-X for patients who died (5.5 +/- 1.6 ng/ml) was significantly less (P < 0.05) than observed for other patient groups. All patients who died had MEG-X values below 10 ng/ml. This suggests that MEG-X testing could be an extremely useful test in the evaluation of patients for hepatic transplantation by identifying persons at increased risk for developing complications of chronic liver disease.

Liver regeneration and function in donor and recipient after right lobe adult to adult living donor liver transplantation.

BACKGROUND: Regeneration of the liver to a predetermined size after resection or transplantation is a well described phenomenon, but the time course over which these events occur has not been well defined. It is not clear how initial liver mass, reperfusion, immunosuppression, or steatosis influence this process. METHODS: Liver regeneration was assessed prospectively by volumetric magnetic resonance imaging (MRI) in living right lobe liver donors and the recipients of these grafts. Imaging was performed at regular intervals through 60 days after resection/transplantation, and liver mass was determined. Liver function tests and synthetic function were monitored throughout the study period in donors and recipients of these grafts as well as recipients of cadaveric grafts. RESULTS: MRI consistently overestimated liver mass by a mean of 45 g (+/-65) (range 10-123). Donor liver mass increased by 101%, 110%, 115%, and 144% at 7, 14, 30, and 60 days after resection, respectively. Recipient liver mass increased by 87,101, 119, and 99% at 7, 14, 30, and 60 days after transplantation, respectively. Steatosis did not influence the degree of regeneration or graft function, nor was there a functional difference between grafts of >1% graft to recipient body weight ratio or <1%. CONCLUSIONS: MRI accurately determines right lobe mass. Most liver regeneration occurs in the 1st week after resection or transplantation, and the time course does not differ significantly in donors or recipients. The mass of the graft or remnant segment affects the duration of the regeneration process, with a smaller initial liver mass prolonging the course. Steatosis of <30% had no bearing on liver function or regeneration and, therefore, should not be an absolute criterion for exclusion of donors. A calculated graft to recipient body weight ratio of 0.8% is adequate for right lobe living donor liver transplantation.

Emergency adult to adult living donor liver transplantation for fulminant hepatic failure.

BACKGROUND: The high mortality rate associated with fulminant hepatic failure combined with the limited availability of cadaveric organs requires consideration of alternatives to conventional cadaveric transplantation. Use of the donor right lobe in adult-to-adult living donor transplantation holds promise in a variety of circumstances, including high-acuity situations. METHODS: A 28-year-old male with fulminant hepatic failure secondary to hepatitis B was referred to our institution. He rapidly progressed to grade IV encephalopathy, and laboratory values were indicative of a poor prognosis without transplantation. He was listed for transplantation as UNOS status I. Three siblings were simultaneously evaluated for living liver donation. Following established protocols, we completed donor evaluation in less than 24 hr, and donor right lobectomy and living donor transplantation were performed within 36 hr of the recipient's admission to our center. RESULTS: The donor surgery was uncomplicated, and the patient was discharged on postoperative day 4. The recipient experienced full recovery and was discharged home on postoperative day 14. Of note, the first offer for a cadaveric liver came more than 60 hr after living donor transplantation. CONCLUSIONS: Thorough donor workup can be completed in less than 24 hr without inappropriate abbreviation of the evaluation. Simultaneous workup of willing individuals prevents unnecessary delay. Living donor transplantation should be considered for patients with fulminant hepatic failure who are appropriate transplant candidates.

Emergency portacaval shunt for control of hemorrhage from a parenchymal fracture after adult-to-adult living donor liver transplantation.

As more adults undergo transplantation with partial liver grafts, the unique features of these segments and their clinical significance will become apparent. A patient presented with life-threatening hemorrhage from an iatrogenic laceration to a right lobe graft 11 days after transplantation. The creation of a portacaval shunt effectively controlled the bleeding, allowing more elective replacement of the organ with another right lobe graft. The regeneration process combined with increased portal blood flow and relative outflow limitation may have set the stage for this complication. Any disruption of the liver parenchyma during transplantation should be securely repaired and followed cautiously. Portacaval shunting is an option for controlling hemorrhage from the liver in transplant recipients. The timely availability of a second organ was likely the ultimate determinant of survival for this patient.

A prospective randomized trial of mycophenolate mofetil with neoral or tacrolimus after orthotopic liver transplantation.

BACKGROUND: The success of liver transplantation in this decade has become the stimulus to extend the donor and recipient pool. Reducing early posttransplant morbidity to maintain our success, as we expand our frontiers, has led us to focus on balanced testing of multidrug immunosuppression regimens. METHODS: A prospective trial in orthotopic liver transplantation using Mycophenolate Mofetil and an identical steroid taper with randomization of patients to Neoral (N) or Tacrolimus (FK) is the basis of this report. This was an intent-to-treat study designed to compare the 6-month primary endpoints of rejection and infection and to compare the 6-month secondary endpoints of liver function, renal function, bone marrow function, hypertension, and serum cholesterol levels. RESULTS: Ninety-seven patients completed the 6-month follow-up period (N=49, FK=48). The actual 6-month patient and graft survival rates were 98% and 94%, respectively. There was no difference in the number of patients with rejection episodes (N=11, FK=8) (P=0.61). There were 24 infections (3 cytomegalovirus) in the FK group and 30 infections (9 cytomegalovirus) in the N group. The cholesterol levels at 6 months were not significantly different (P=0.07) between the groups. The other secondary 6-month endpoints were not significantly different, except total bilirubin, which was lower in the FK arm (P=0.02). CONCLUSIONS: The use of Mycophenolate Mofetil with N or FK and an identical steroid taper after orthotopic liver transplantation is associated with excellent graft and patient survival, and at 6 months, only 191% of the patients experienced rejection, with a 48% overall infection rate.

The impact of a positive crossmatch upon outcome after liver transplantation.

Recent reports have shown that liver allografts transplanted against a positive lymphocytotoxic crossmatch (CDC+) are susceptible to an increased frequency of rejection, and decreases in patient and graft survival. The implication of a positive flow cytometric crossmatch (FCXM+) in liver transplantation remains controversial. The purpose of this study was to determine what impact a pretransplant IgG crossmatch due to CDC+ or FCXM+ had upon the clinical outcome following liver transplantation. Preoperative crossmatch status was determined prospectively in 110 consecutive liver transplants performed between July 1991 and January 1995. Allografts were divided into three groups: negative crossmatch (NXM), positive flow cytometric crossmatch FCXM+, and positive lymphocytotoxic crossmatch CDC+. Crossmatch status did not impact patient or graft survival. Actuarial patient survival was similar between groups at 12 months (88% vs. 95% vs. 92%, NXM vs. FCXM+ vs. CDC+) and 24 months (81% vs. 93% vs. 92%, NXM vs. FCXM+ vs. CDC+) (P=0.1938). Actuarial allograft survival was similar between groups at 12 months (76% vs. 93% vs. 85%, NXM vs. FCXM+ vs. CDC+) and 24 months (76% vs. 89% vs. 85%, NXM vs. FCXM+ vs. CDC+) (P=0.0738). CDC+ allografts had a significant increase in early rejection episodes compared with NXM (46% vs. 7%, CDC+ vs. NXM) (P=0.003) or FCXM+ allografts (46% vs. 10%, CDC+ vs. FCXM+) (P=0.006). CDC+ allografts experienced significantly more rejection episodes per year than NXM (53% vs. 20%, CDC+ vs. NXM) (P=0.015) or FCXM+ allografts (53% vs. 23%, CDC+ vs. FCXM+) (P=0.02). CDC+ allografts had a significant increase in numbers of additional nonconventional therapeutic interventions compared to NXM allografts (0.9+/-0.5 vs. 0.2+/-0.1, CDC+ vs. NXM) (P=0.039). The presence of cytotoxic antibodies pretransplantation is associated with increased incidences of early rejection, and rejection episodes per year. With careful monitoring and aggressive therapeutic interventions the presence of cytotoxic antibodies are not deleterious to patient or liver allograft survival.

Selection and outcome of living donors for adult to adult right lobe transplantation.

BACKGROUND: The shortage of cadaveric livers has sparked an interest in adult-to-adult living donor transplantation. Right lobe donor hepatectomy is frequently required to obtain a graft of adequate size for adult recipients. Careful donor selection is necessary to minimize complications and assure a functional graft. METHODS: A four-step evaluation protocol was used for donor selection and satisfactory results of all tests in each step were required before proceeding to the next. Donors were selected based on a battery of laboratory studies chosen to exclude unrecognized infection, liver disease, metabolic disorders, and conditions representing undue surgical risk. Imaging studies included ultrasonography, angiography, magnetic resonance imaging, and intraoperative cholangiography and ultrasonography. The information obtained from liver biopsy was used to correct the estimated graft mass for the degree of steatosis. RESULTS: From March 1998 to August 1999, 126 candidates were evaluated for living donation. A total of 35 underwent donor right lobectomy with no significant complications. Forty percent of all donors that came to surgery were genetically unrelated to the recipient. A total of 69% of those evaluated were excluded. ABO incompatibility was the primary reason for exclusion after the first step (71%) and the presence of steatosis yielding an inadequate estimated graft mass after the second step (20%). CONCLUSIONS: Donor selection limits the application of living donor liver transplantation in the adult population. Unrelated individuals increase the size of the donor pool. Right lobe hepatectomy can be performed safely in healthy adult liver donors. Preoperative liver biopsy is an essential part of the evaluation protocol, particularly when the estimated graft mass is marginal.

Management of interferon therapy nonresponders.

Despite improvements in the therapies for chronic hepatitis C virus (HCV) over the past several years, many patients still fail to become hepatitis C virus ribonucleic acid (HCV-RNA) undetectable during treatment and are classified as nonresponders. Providing treatment recommendations for these patients requires that the likelihood of achieving any benefit from another course of therapy be balanced with the natural history of chronic HCV. The management of nonresponders represents the most challenging of all aspects in the care of patients with chronic HCV. Retreatment of interferon non-responders with interferon and ribavirin has yielded a long-term virologic benefit in only 10% to 25% of patients. The efficacy of peginterferon and peginterferon with ribavirin for nonresponders has yet to be defined.

Benign recurrent intrahepatic cholestasis.

Benign recurrent intrahepatic cholestasis is a rare autosomal recessive disorder characterized by repeated episodes of intense pruritus and jaundice. Each attack lasts from several weeks to months before resolving spontaneously. Patients are completely asymptomatic for months to years between symptomatic periods. The disorder does not lead to progressive liver disease. Although attacks seem to be associated with a viral prodrome, an inciting viral agent or toxin has not been defined. Genetic studies have mapped the defect of this disorder to the long arm of chromosome 18 and a gene that codes for a P-type ATPase, which appears to be involved in aminophospholipid transport. Therapy during symptomatic periods is supportive and aimed at relief of severe pruritus until the episode resolves spontaneously.

A prospective, randomized-controlled pilot study of ursodeoxycholic acid combined with mycophenolate mofetil in the treatment of primary sclerosing cholangitis.

BACKGROUND: Ursodeoxycholic acid has been ineffective in the treatment of primary sclerosing cholangitis. Because the pathogenesis of primary sclerosing cholangitis is related to immune destruction of bile duct epithelium, several immune suppressive agents have been evaluated. Mycophenolate mofetil is a potent immunosuppressant that is now widely used in organ transplantation. AIM: In this pilot study to determine if mycophenolate mofetil when combined with ursodeoxycholic acid could prevent evidence of clinical progression and improve the biochemical, histological and/or cholangiographic features of primary sclerosing cholangitis compared with patients treated with ursodeoxycholic acid alone. METHODS: Twenty-five patients with well-defined primary sclerosing cholangitis were randomized to ursodeoxycholic acid (13-15 mg/kg/day) with or without mycophenolate mofetil (1000 mg b.d.). Cholangiography and liver biopsy were performed at study entry and after 2 years of treatment. Symptoms, clinical features of liver disease and biochemical tests were monitored at 3-month intervals. RESULTS: The mean age 44 years, 58% male, 84% Caucasian and 64% had ulcerative colitis. After 2 years, there were no differences in laboratory values, histological stage or cholangiograms between patients treated with ursodeoxycholic acid alone and those treated with mycophenolate mofetil + ursodeoxycholic acid. CONCLUSIONS: Mycophenolate mofetil combined with ursodeoxycholic acid does not appear to provide additional benefit compared with standard doses of ursodeoxycholic acid alone in the treatment of primary sclerosing cholangitis.

Alpha interferon combined with ribavirin potentiates proliferative suppression but not cytokine production in mitogenically stimulated human lymphocytes.

The improved clinical outcome observed among patients with hepatitis C treated with the combination of alpha interferon (IFN) and ribavirin (RBV) is presumed to result from immunomodulation and viral inhibition. However, the impact of the drug combination upon lymphocyte activity is unknown. The present study evaluated the effects of IFN and RBV, singly and in combination, upon proliferation, cell cycle sensitivity and cytokine elaboration following PHA stimulation of lymphocytes. Two formulations of IFN, interferon-a-2b (IFN-2b) and interferon-a-con-1 (CIFN), were included. Titration of each drug over a wide range of concentrations showed dose dependent proliferative suppression without cytotoxicity. Proliferation was suppressed 57-99% (P<0.001) by IFN-2b (10(5)-10(7) IU/ml), 41-74% (P<0.001) by CIFN (1.5-150 ng/ml), and 10-94% (P<0.001) by RBV (0.5-50 microg/ml). Isobologram analysis showed that the interaction between IFN-2b and RBV on proliferative suppression was additive. In contrast, the interaction between CIFN and RBV was weakly antagonistic. Proliferative suppression by both the IFNs was cell cycle restricted. IFN-2b and CIFN added at the onset of PHA stimulation (G0/G1) versus 24 h later (S phase) inhibited proliferation by 50 versus 5%, respectively (P<0.05). The onset of IFN resistance correlated with a 50% reduction (P<0.05) in IFN receptors on the cell surface. In contrast, RBV caused equivalent proliferative suppression (P=NS) when added at any time during PHA activation. Cytokine secretion after 24 h of PHA stimulation showed that IFN-2b versus CIFN increased the secretion of IL2, TNF and gamma IFN by 4.5-, 4.1- and 8.3-fold (P<0.005) versus 1-, 1.9- and 1.9-fold (P<0.05), respectively, above control levels. Neither IFN affected IL10 secretion. RBV, singly and in combination with IFN, had no impact on cytokine expression (P=NS). This study identifies several potential mechanisms by which the combination of IFN and RBV may exert a more potent effect upon cellular immunity than either agent alone and shows that different formulations of IFN may have non-identical effects upon lymphocyte responses.

A multicenter, placebo-controlled, randomized, double-blind, prospective trial of prophylactic ursodiol for the prevention of gallstone formation following gastric-bypass-induced rapid weight loss.

BACKGROUND: Previous studies have documented a high incidence of gallstone formation following gastric-bypass (GBP)-induced rapid weight loss in morbidly obese patients. This study was designed to determine if a 6-month regimen of prophylactic ursodiol might prevent the development of gallstones. METHODS: A multicenter, randomized, double-blind, prospective trial evaluated 3 oral doses of ursodiol: 300, 600, and 1,200 mg versus placebo beginning within 10 days after surgery and continuing for 6 months or until gallstone development, for patients with a body mass index (BMI) > or = 40 kg/m2. All patients had normal intraoperative gallbladder sonography. Transabdominal sonography was obtained at 2, 4, and 6 months following surgery, or until gallstone formation. RESULTS: Of 233 patients with at least one postoperative sonogram, 56 were randomized to placebo, 53 to 300 mg ursodiol, 61 to 600 mg ursodiol, and 63 to 1,200 mg ursodiol. Preoperative age, sex, race, weight, BMI, and postoperative weight loss were not significantly different between groups. Gallstone formation occurred at 6 months in 32%, 13%, 2%, and 6% of the patients on the respective doses. Gallstones were significantly (P < 0.001) less frequent with ursodiol 600 and 1,200 mg than with placebo. CONCLUSION: A daily dose of 600 mg ursodiol is effective prophylaxis for gallstone formation following GBP-induced rapid weight loss.